package day3;

public class Demo11 {
    public static void main(String[] args) {

        char[] nums = new char[36];
        Char(nums);
        CheakCode(nums);


    }

    public static void CheakCode(char[] nums){
        for (int i = 0;  i < 4; i++){
            System.out.print(nums[(int)(Math.random()*36)]);
        }

    }

    public static void Char(char[] nums){
        for (int i = 48; i < 58; i++){
            nums[i-48] = (char)i;
        }
        for (int i = 65; i < 91; i++){
            nums[i - 65 + 10] = (char)i;
        }
        for (int i = 0; i < nums.length; i++){
            System.out.print(nums[i] + "\t");
        }
        System.out.println();
    }

}
